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Dependency tracking library for CMake - completely written in CMake.

CMLIB Library is dependency tracking library which allows effectively track all needed dependencies without Worrying about consistency and project regeneration times.

Main features are

• No other dependencies. Only CMake and Git.
• CMake cache regeneration - once the dependency is downloaded and cached it's preserved even after build directory deletion
• Dependency cache consistency check – the only dependency even if explicit keywords are specified

For examples look at the example directory

• clone directory by git clone https://github.com/cmakelib/cmakelib.git <path_to_cmakelib_repo>
• export CMLIB_DIR=<path_to_cmakelib_repo>

Small example for Ubuntu 20.04

FIND_PACKAGE(CMLIB REQUIRED)

CMLIB_DEPENDENCY(
	# We use koudis/boost-prebuilt-binaries
	URI "https://bit.ly/3rQsAXd"
	TYPE ARCHIVE
	OUTPUT_PATH_VAR BOOST_ROOT
)
FIND_PACKAGE(Boost 1.76.0 COMPONENTS log_setup log REQUIRED)

Full example can be found at example/DEPENDENCY/boost_example

• CMake >=3.18 installed and registered in PATH env. variable
• Git installed and bin/ directory of git registered in PATH env. variable

It is intended that the user has only one global instance of library. However it is possible use cmakelib as submodule but it is not recommanded.

Library is stored on User computer and the global CMake variable CMLIB_DIR must be defined.

• Choose directory where cmakelib will be stored. We will call this directory <cmlib_root>
• Clone repository to local computer to <cmlib_root>
• Define System ENV var CMLIB_DIR as absolute path to already cloned repository
• You may define system ENV var CMLIB_REQUIRED_ENV_TMP_PATH to path to existing directory. This variable represents Cache directory where the cache will be stored. If not set the "${CMAKE_CURRENT_LIST_DIR}/_tmp" is use instead.
• call FIND_PACKAGE(CMLIB REQUIRED)
• Everything should works fine now

Examples for CMLIB_DEPENDENCY can be found at example/DEPENDENCY

The library core is a function

CMLIB_DEPENDENCY

Which can track/cache various number of dependencies.

System modules do not contain anything except what is needed for CMLIB_DEPENDENCY implementation.

Library consist from following system modules

• CMLIB_DEPENDENCY - track and cache remote dependencies (under remote dependency we assume dependency which is not 'directly' attached to the user CMake project)
• CMLIB_REQUIRED_ENV which init base environment for library needs
• CMLIB_CACHE - cache files on host filesystem (represent persisten cache)
• CMLIB_FILE_DOWNLOAD - download file from remote HTTP URl or GIT repository
• CMLIB_PARSE_ARGUMENTS - wrapper around cmake_parse_arguments
• CMLIB_ARCHIVE - extract files from archive
• CMLIB_COMPONENT - component logic

Detailed documentation can be found in each module.

There are examples for each modules in example directory.

As optional feaure CMake-lib provides several components which extends functionality of the core library.

Each component has its own git repository in form cmakelib-component-<component_name>.

The master branch of the given component is always used.

List of CMake-lib components

• CMLIB_STORAGE - effectively track build resources,
• CMDEF - well defined built environment,

Components can be used by FIND_PACKAGE(CMLIB REQUIRED COMPONENTS <component_list>)

Cache entries are represented by ordered, nonempty set of uppercase strings called KEYWORDS.

If no KEYWORDS are specified then the set is created by the library as hash of URI, GIT_PATH etc.

Cache mechanism is persistent across CMake binary dir instances. If user deletes our CMake binary dir the cache will regenerate in next CMake run for the same CMakeLists.txt (we assume that cache is located in dir different from CMake binary dir)

If the CMLIB_REQUIRED_ENV_TMP_PATH is set then the cache will be stored in the directory specified by CMLIB_REQUIRED_ENV_TMP_PATH.

If the cache reset is needed, just delete directory path stored in CMLIB_REQUIRED_ENV_TMP_PATH.

Dependency cache control is optional feature (enabled by default) which ensure that there are only one dependency cached at a time.

If ON we cannot track one dependency under two different KEYWORDS sets.

Mechanism can be disabled by setting CMLIB_DEPENDENCY_CONTROL to OFF.

All temporary files and outputs are stored in temporary directory

Path to temporary directory is controlled by CMLIB_REQUIRED_ENV_TMP_PATH

CMLIB_REQUIRED_ENV_TMP_PATH can be overridden be system ENV var named CMLIB_REQUIRED_ENV_TMP_PATH

User can define global ENV var to specify one, central cache storage which will be shared across CMake project instances.

• Each cache entry is represented by ordered set of keywords. It's common idiom the the first keyword is name of the project in which the CMLIB_DEPENDENCY/CMLIB_CACHE is written.
• Use CMLIB_DEPENDENCY instead of other CMLIB functions. (use other only if you known what you are doing)

• CMLIB_REQUIRED_ENV_TMP_PATH - where to store tmp path where the cache will be stored. Can be set as Environment variable (which must be accessible by $ENV{CMLIB_REQUIRED_ENV_TMP_PATH}). Default value is "${CMAKE_CURRENT_LIST_DIR}/_tmp". More info at CMLIB_REQUIRED_ENV
• CMLIB_DEPENDENCY_CONTROL - Boolean variable which controls if the Dependency cache control is enabled. CMLIB_DEPENDENCY
• CMLIB_FILE_DOWNLOAD_SHOW_PROGRESS - if ON show HTTP download progress. If OFF do not show http download progress
• CMLIB_FILE_DOWNLOAD_GIT_ARCHIVE_DISABLE - if ON no git archive is used for downloading resources from the remoe git repository.
• CMLIB_FILE_DOWNLOAD_GIT_ARCHIVE_ONLY - If ON the git archive functionality is required for downloading resouces from remote git repository. OFF value has no effect to standard workflow

For test go to the test/ directory and run

Linux/Mac Os:

	GIT_TERMINAL_PROMPT=0 cmake .
	GIT_TERMINAL_PROMPT=0 cmake -P ./CMakeLists.txt

Windows PowerShell:

	$env:GIT_TERMINAL_PROMPT=0
	cmake .
	cmake -P ./CMakeLists.txt

then just clean up all intermediate files by

git clean -xfd

In library we use Uppercase for all CMake keywords.

Local variables can be named as lowercase.

Just call "git pull" on repository root.

In case of cmake-generation problem reset cache.

Project is licensed under BSD-3-Clause License